i. Field of the invention
This invention relates to forming powder from metal swarf.
II. Description of the Prior Art
If not reclaimed, the metal swarf removed from workpieces during machining operations represents a considerable loss of metal. Thus it is usually collected and sold as scrap, typically in the form of bales. Such scrap is not however in a conveniently reusable form for most purposes, being contaminated with oil, grease and dirt, Proposals have therefore been made to put the swarf into a more convenient form by fragmenting the swarf particles to a maximum particle size of 6 mm and removing oil from the fragments. These fragments can be reduced to powder by milling operations but difficulties arise in the milling as a result of the ductility and hardness of the metal. Moreover the powder is obtained in a fully work-hardened condition and although it can be used for compacting and forging into components the particle size of the powder that is conveniently attainable is too large for conventional powder compaction units. Re-tooling is therefore necessary, but even then the components produced from such particles are of relatively low quality.